Soap bars have long been employed for washing the human body and for "doing laundry". Before the advent of washing machines dictated the employment of detersive materials in powder, disintegrable briquette or liquid forms, laundry was washed with "laundry soap" bars made from suitable soaps of higher fatty acids, such as sodium soaps of mixed tallow and rosin fatty acids. Such laundry soap bars were especially suitable for being rubbed onto badly stained or soiled portions of fabrics being laundered, as on a washboard, to deposit a high concentration of the soap on the soiled area, and they provided mechanical means for applying energy to such surfaces to assist in removing the stains and soils.
Despite the fact that after the introduction of synthetic organic detergents and washing machines the amount of soap employed for laundry use diminished greatly, soap in bar or cake form is still the personal cleaning agent of choice in most of the world, and laundry soaps and detergents in bar form are also still preferred by many consumers in various regions. Detergent laundry bars based on alkylbenzene sulfonate detergents have been successfully marketed. They have been characterized as the equivalents in washing abilities of powdered laundry detergents based on similar alkylbenzene sulfonates, and are considered by many consumers to be more convenient to use. To use them does not require the purchase of a washing machine and, as was previously indicated, the bar form of the product allows it to be used in such manner that a comparatively high concentration of detersive material may be readily applied to a heavily stained or soiled area with accompanying physical force or energy, as on a washboard, so as more readily to loosen and remove such soil or stain.
Efforts to incorporate antibacterial agents into laundry products have been well known. They are to sanitize the clothes and remove germs for an antiseptic wash. Many bactericides, such as trichloro carbanilide, diphenyl ethers etc. have been tried. The use of these compositions has not been satisfactory because of their high cost when used at useful levels. In addition the compounds frequently break down at high pH or under high temperature processing conditions. In addition high levels of fragrances have to be used to maintain an adequate scent to the final product.